French polling institutes will not release exit polls or projected results for the presidential election on Sunday before voting ends at 8 p.m. (1800 GMT), the polling watchdog said on Friday.

A 1977 law bans the publication of polls during the election weekend to avoid influencing the vote. But in the past, foreign media have published estimates based on partial vote counts in provincial polling stations, which close at 6 p.m. (1600 GMT), two hours before the big cites.

At the last presidential election in 2007, Belgian and Swiss media released early projections on their French-language websites, widely consulted in France.

The polling watchdog, fearing that social media such as Facebook and Twitter may spread early estimates even faster this time, said it had agreed an embargo with polling firms and would sue any French or foreign media that break the embargo.

The agency said France's nine main polling institutes had agreed not to conduct any exit polls and would not release projections based on provisional vote counts to the media.

I want to contradict the idea that the law is obsolete just because it was adopted in a prehistoric period, before Facebook, Twitter or even the Internet, Polling Commission President Marie-Eve Aubin told reporters.

All voters have the right to the same information and early result projections might unduly influence late voters, she said.

Anyone who publishes early vote projections on any platform, including social networking sites, faces a fine of 75,000 euro ($98,600) or up to 375,000 euros for a company, she said.

President Nicolas Sarkozy called the rules outdated and told RTL radio he would not be shocked if citizens consulted foreign websites about voting projections.

Everyone has a computer. Can we put up a digital barrier? Should we scramble people's computers? What kind of world are we living in? he asked.

But Aubin said the 1977 law remained in force and the commission had made arrangements with the Paris prosecutor to swoop on any media group that published exit polls or early results.

Pollsters will still conduct projections of the outcome based on early ballot counts and distribute them to paying customers, mainly TV and radio stations, under embargo, to be published once all polling stations have closed.

Political parties, which also get early access to vote count projections, will also be held to discretion, Aubin said.

She added that attempts to mask poll projections on Twitter with coded language, as well as any links to or pick-ups of stories about projections would also be considered as publication.

Some of these codes are just too transparent, Aubin said, adding that this would not be an excuse.

Several French blogs have discussed the possibility of referring to Sarkozy and his Socialist challenger Francois Hollande as Hungary (Sarkozy is of Hungarian descent) and Holland as well as with other nicknames.

We want the vote to be serene and without interference. Anyone who breaks the law will be sued. We hope our dissuasion will be effective, Polling Commission Secretary-General Mattias Guyomar said.

(Reporting by Geert de Clercq and Gerard Bon; writing by Geert De Clercq; editing by Paul Taylor)